15-Hydroxyprostaglandin Dehydrogenase Inhibitor Restores Endothelial Function Under Dihydrotestosterone-Induced Stress in Human Dermal Microvascular Endothelial Cells

Androgenetic alopecia (AGA) is closely associated with oxidative stress and vascular dysfunction, which disrupt nutrient delivery to hair follicles and promote follicle miniaturization. Dihydrotestosterone (DHT) exposure impairs human dermal microvascular endothelial cell (HDMEC) function by inducing mitochondrial disruption, excessive reactive oxygen species (ROS) accumulation, and reduced angiogenic capacity. This study evaluated the protective effects of dihydroisoquinolinone piperidinylcarboxy pyrazolopyridine (DPP), a novel 15-hydroxyprostaglandin dehydrogenase (15-PGDH) inhibitor identified through the AI-based discovery platform DeepZema^®, in DHT-exposed HDMECs. DPP markedly reduced intracellular and mitochondrial ROS levels, restored mitochondrial membrane potential, and increased ATP production, thereby alleviating oxidative stress and supporting mitochondrial function. DPP also enhanced endothelial cell migration and capillary-like tube formation, demonstrating the restoration of angiogenic capacity that is essential for sustaining perifollicular vascularization. Moreover, DPP mitigated stress-associated signaling by reducing the phosphorylation of ERK, JNK, and p38 within the MAPK pathway, thereby suggesting the reestablishment of endothelial homeostasis under DHT-induced stress. Collectively, these findings indicate that DPP preserves endothelial function under DHT-driven oxidative conditions. We suggest that DPP may exert complementary protective effects on both vascular and follicular compartments, supporting its potential relevance in hair follicle regeneration.